The invention relates to an internal combustion engine with a constructed piston, consisting of a piston head made of steel and a lower piston part that are connected with one another by way of a single screw arranged in the center axis or close to the center axis of the piston, and with a central cooling space between the piston head and the lower piston part, furthermore with an oil-carrying connecting rod that is connected with the lower piston part by means of a piston bolt.
A piston for an internal combustion engine of this type is known from DE 4131275. In the case of this piston, the cooling oil is introduced, by way of the piston bolt, into the hubs and from there into bores that run vertically, towards the top, into an outer cooling channel, it flows radially towards the inside into a central cooling space, and into the inner form of the piston by way of a run-off.
Because the oil is deflected in the piston bolt and through the long bores, there is a relatively high flow resistance. The invention is therefore concerned with the problem of optimizing the flow of the cooling oil through the piston, and of simplifying the bolt by means of an oil guide that is not integrated into it, i.e. optimizing it in terms of strength.
This problem is solved by means of the characterizing feature of claim 1. Advantageous further developments are the object of the dependent claims. Sliding blocks for conducting oil into a central cooling space are actually known, for example from DE 3518721, FIG. 3. However, a combination of a central screw connection and a sliding block has not been proposed until now, although both characteristics in and of themselves have been known for a long time, since both characteristics are generally arranged at the same location, i.e. in the center axis of the piston in the region of the inner form, and for reasons of space, it hardly appeared possible to implement both characteristics at the same time.
An integration of the two characteristics is taught by the solutions shown.